<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>属性选择器</title>
    <style>
      [type]{
          color: blueviolet;
      }
    </style>
</head>
<body>
用户名;<input type="username"><br/>
密码;<input type="password"><br/>
邮箱;<input type="email"><br/>
</body>
</html>